The investigator's goal is to understand the mechanism and regulation of flagellar motility. They have taken advantage of the powerful genetic tools available in Chlamydomonas, coupled with newly developed techniques to tag and clone genes by insertional mutagenesis, to begin a molecular dissection of function of the central pair complex of the flagellar axoneme. The specific aims are: 1) to clone and characterize additional genes for central apparatus components; 2) to identify proteins interacting with components of the central apparatus; 3) to define functional domains required for assembly and function of individual central apparatus components using in vitro mutagenesis. The amramdillo repeat protein PF16, will be the first target for detailed molecular analysis. The investigator states that the study of central apparatus components will not only have an impact on the field of flagellar motility but also on the fields of motor regulation and microtubule function.